Answer-back signal.



ErR. GILL.

ANSWER BACK SIGNAL. APPLIGATION 11.21) JULY'27, 19o'z..

Patentd Dec. 13,1910.

5 sums-sum 1.

E. R. GILL.

' ANSWER BACK SIGNAL. nrmoumx rmm JULY 27, 1001.

Patented Dec. 13,1910.

5 BHEETB-BHEET 2.

E. R GILL. ANSWER BACK SIGNAL. nrmonxon FILED JULY 27, 1901.

Patented Dc.13,1910.

' a sums-sum a.

W A. 4J4 51 mm Mao-z or} 3151: 6111011411 R. GILL. I

ANSWER BACK. SIGNAL.

APPLXOATIOI rILnn JULY 21, 1901.

" Patnted 1m 13,1910.

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' 5 vwe do-z E. R. GILL.

ANSWER BACK SIGNAL.

AYBLIOATION FILED JULY 27. 1907.

Patented Dec. 13, 1910.

5 SHEETS-SHEETS.

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i f vent-ion that the pcrsoncalled will know, on

city of Yonkers, county of West-chestcr, and

ring the selective call may know whether or tionin the rheantime.-

STATES PATENT OFFICE.

EDWIN pr onKERs. NEW YORK, ASSIGNOR fro-UNITED STATES ELECTRIC ooMPANY.A CORPORATION or WEST VIRGINIA.

ANSWER-BACK. SIGNAL.

Specification of Letters Patent.

Application filed July 27, 1907. Serial No; 385,844 Y To all azliom canmam;

Be it known that l, EDWIN R:. GILL, a citizen of the United States,reslding in'the State of New York, have invented a certain new anduseful Improvement in Answer- Back: Signals, of which the following is aspecificaiicn. y

Many devices have been invented for the purpose of operating selectivelyata distance any one of a number of signals for calling stations on acommon main line cir- (mil; in such a manner that only the one stai nWanted shall receive a call. Where instruments of this kind areemployed, it often becomes im ortant to be able to ascer tain positivelyw ether or not the call has been successful and whether the'rightstation instrument has responded to the mainline impulses.

The present invention has relation generally to means for the purposeabove named, and. in its preferred form'this invention is so organlzedthat an intelligible signal is returnedwhereby the person sendnot the.call hell or equivalent. device is. actually in working order;

One feature of mypreferred inventionis intended to insure preservationof the main line circuit in case'of accidents happening to'any one ofthe answer back devices, so that an a'ccident to one instrument may notcripple any other.

Another advantage of my preferred invention is that, in case theoperator calledshould be a.bsent, the call signal will continue itsoperation indefinitely fund such operation will not be interfered withby arriyal of additional calls at the same sta- It is also a feature ofthis form of my inhis return, how many; calls have come in during hisabsence, by mere inspection of his instrument. My apparatus may be usedinconnection with telegraph or telephone lines, and in the preferredform herein described, wherein are combinedall of the advanta es above inamed, I have shown-the use of 0th tele gra hand telephone instruments.

his invention also has "relation. to ceraselector herein,

tain details of improvement hereinafter described and particularlyreferred to in my claims.

Patented Dec. 13, 1910.

A preferred form of, my invention is shown in the accompanying drawings,where1n- Figure 1 is a plan view of the combined answer back and localsignal operator, .Fig. 2 is a side elevation of the same, a verticalsection thereof. on the plane wm in Fig. 1,-the armature springabutmentbe 111g shown in mid-section, Fig. 4 is a detail of the release for theoperating train, Fig. 5 is a side elevation on-the side opposite to thatshown in Fig. 2 and Fig. 6 is a diagram of circuits.

It is to be understood that my present invention is intended for andadapted to use in connection with any desired form or style of selectivesignaling device, and may indeed be used in combination with any meansvfor operating it from a distance, whether Fig. 3 is such means includesa selector or not. I have therefore omitted all description of the andin Fig. 6 have indicated as'an example merely, the type of selectivecall described and claimed in my Patent Number 906,523, dated Whilecertain forms of my invention may be advantageously employed inconnection with anyappropriate motive power, it is most usefullyemployed on telegraphic and tele honic lines, and I have therefore shownherein a preferred embodiment of the in- December 15th, 1908.

vention as adapted to'be operated by elecv tricity. v I

In the .form shown, the combined answer back and local signal is mountedupon a I base 1 and supported by framework 2 at or near one end of whichis placed the operating magnet 3, pvhose vertical swinging armature 4 ispreferably supported by a thin spring 5. n'e extremity bowed strapspring6 is fixed to the lower end of the armature 4 and the opposite end ofthis spring is fixed to a movable clamp 7 adapted to be moved back" andforth for adjustment-under tho influencejof the screw 8 passing throughthe abutment 9. i

The spring 6 is intended to directly operate and release theretainingdevice for the answer back actuating train, which, in the formshown, preferably comprises a subof a normally.

stantially upright rod fixed to a revoluble shaftill to which is alsofixed a bent arm 12 whose, outer'extremity lies across the middleportion of the spring 6.

hen-the magnet 3 is energized, by op;

eration of the-selective call or otherwise, the armature is attractedand the spring 6 1s straightened, as shown in dotted lines in Fig. '3..This lifts the arm 12 and releases particular instrument correspondingto said [shown in dotted lines in Fig. 2.

code signal has'been successfully called. In the preferred form shownthis consists of a make and break wheel for an appropriate circuit. ()nesuitable form of such a wheel is shown at 13 in Figs. 1, 2 and (3. saidwheel carrying teeth 14 set around its circumference at suitableintervals. 'lhese teeth have inclined backs, so that when the wheel isturned in the direction of the arrow in Fig. 2 the tip of the contactspring 15 shall be lifted to the summit of each tooth in succession.

The contact .s'pring 15 is carried upon a fixed insulating support 16,secured at 17, so that, when the wheel 13 turns, the tip of the spring15 dips by its own resilience into each space between two teeth l-t insuccession, but not far enough to make contact with the bottom of saidspaces. This is The contact thus successively made and broken betweenthe spring 15 and the wheel 1?) is utilized to make and break the answerback circuit as described hereinafter in connection with Fig. 6.

In the form shown the wheel 13 is moved by 'a gear f'train as follows.One end of a coiled driving spring 18 is" secured to a cross bar 19fixed to the frame 2, while the other end of said spring is fixed toa'main slow moving shaft 20, which is reset (winding the spring 18) bymeans of the handle 21, after operation of the answer back. The normalposition of the handle illwvith the spring 18 fully wound is shown inFig. 2.

The main shaft 20 carries the ratchet wheel 22 which engages with aspring pressed pawl 23 pivoted on one face of the driving gear 24 in awell known manner, said gear being loose on the shaft 20. The drivinggear 9A drives the shaft 25 through the pinion 26, and the answer backwheel 13 is carried on said shaft 25. For obvious reasons it isadvisable to apply a retarding device to the train so far described andI prefer for this purpose, to employ a toothed wheel 27 and weightedswinging escapement 28 driven by a gear wheel 29' on the shaft 25, inthe manner shown in F1g. 3.

Movement of this spring driven gear train is normally prevented by apeg.30 on the face of the wheel 29 which rests upon a lat eral bend atthe end of the rod 10 (see Figs. 3 and 4). It will thus be seen that,when the rod 10 assumes the dotted line position (shown in Fig. 3) underthe influence of the magnet 3, the train is liberated.

For the purpose of use in connection with selective calls on telegraphlines I prefer to arrange the train release so that it requires a doubleor forth and back movement of the retaining device to permit the trainto move. For this purpose a second peg 31 is fixed on the check wheel20. a little nearer the center and normally above the peg 30, As thusarranged. the magnet 3' acts to tilt the rod 10 as shown in dottedlines. when the train will move -until the peg 31 touches the tip of therod 10. This position is showzn in dotted lines in Fig. 4. Then. as themagnet releases its arnwture. the rod moves back to the full lineposition and the train is free to move until a complete revolution ofshaft 25 and wheel 13 is produced, when the peg 30 once more strikes therod 10 and themovement is arrested. I

\Vhere. as in the form shown. the local call signal which is set inoperation by the selective calling device is combined mechanically andelectrically with the answer back mechanism, I prefer to mount a localcircuit closing sector on one end of the main driving shaft. 20, as bymeans of the hub 33 and setscrew 34. A stationary spring 35 is mountedupon an insulating support 36 in such a position that. as the sector 32revolves (in the direction of the arrow in Fig. 5) it will make electriccontact with said spring 35 to close the call circuit as described inconnection with Fig. 6. 'Byplacing the long sector 32 on the slow movingmain shaft, the shaft'QF) and answer back wheel 13 may be given three orfour revolutions without causing the sector to lea e the spring- 35.Thus,- ifthe operator should be absent when a call is given and a secondcall comes while the signal is still in operation. such second and eventhird or fourth calls will not interrupt the signal. .At the same time.when the operator returns. the position of the handle 21 will make clearhow many calls have arrived during his absence. The spring 18 isaccordingly made long enough to produce. three or four (or anyreasonable number of) revolutions of the wheel 13.

From what has been described above it. is clear that if the two terminalbinding posts 37 of the magnet 3 be connect ed respectively to the twosides of an electric circuit. and said circuit be alternately closed andopened. the actuating gear train will be released and both the answerback and the cell signal circuit will be operated. "lhese results may besecured by .controlling the magnet circuit a I y from a'distance eitherdirectly or indirectly without departing from my lnventlon; but I preferto accomplish this through a selective i circuit closing apparatus inconnection with a local battery. One way in which this may be ,done isshown in, Fig. .6. This figure shows apref erre d arrangement ofapparatus for use on a telegraph linewhereina number ofstationsafeconnected to asingle main line' wire 38, ,ea'ch of which maybe called from any other by means of an appropriate selectiveinstrument, indicated in diagram at 39. v

' At 40 and 41 are shown respectively a telegraph key and a telephonereceiver which j I are supposed to be located atthe callingstation. Itis to be understood, of course, that the calling station is equipped inthe same I manner asthe station called. Duplication of the totalapparatus has been omitted for convenience and clearness,

At the station'calle'd the relay 42 is pro- .vided with this usualarmature 43,v playing between a forward contact making stop 44 and anelectficallyflistinct' insulated, rear contact piece 45. fOne side of'alocal battery 46 is connected by the wire 47 to the armature 43, whilethe wire 48 connects 'the other pole of the battery 46 tonne terminal 4901 the actuatingma'gnet (not shown) of the selective instrument 39. Theopposite terminal 50 of, this actuating magnet is conv nected by wire 51to theinsulated rear con-' tact piece 45. o I

The forward relay contact piece 44 is co'nnected by thevwire -52 to theusual sounder -53,-thefotherisi e of whichconnects with the battery 46.wire 54.

The termina ls 55, 56 on the selector 39 are those-thrcugh which thisinstrument I closes circuit through the'local battery in a wellzknownmanner, ordinarily for the purpose of directlyringing' the call bell;and

I theseterminalsmay also be utilized for said 1 6 without'departing fromthis invention, so

purpose in addition to that shown in Fig;

faras relates toth'e answer backalone. I prefer, however, to I operatethe answer back and call signal circuit together as hereconnectedto'terniinals 49 and v, sponds to gopen-circuit on the main line, or"

in described, and for this purpose the main operating magnet 3isgconnected on one side to thef'terminal 55 and on the other to thelocal battery 46,while the other terminal 56 is connected to tery. p

'From the above description 't will be seen that each operation of theselector magnet the opposite pole saidhat pauses between depressions ofthe key 40,,

which pauses topermit-the relay armature to touch the contact piece 45/Thus long and "short pauses between depressions of the key produce longand'short action of the inagnet utilized in any in the'selector, whichare left and under the party callin "cessfully op 50 correv well knownmanner to c cra e e e e and close the local circu t through 55 and 56.Thus final closure of the m n l cuit at the end of an op ration d n gizs 'the selector magnet and releases the mechanism so as to break thecircuit previously closed through 55, 56; a fact ad'verted tohereinafter. All these operationsare well known and are producible byvarious highly complicated devices a descripti n f wh h would not add tothe elucidation of this invention and would merely increase thecomplexity of this description and of the drawings.

' The mode of operation of'the apparatus thus .far described is asfollows.The sending key 46 being grounded at G and one side of the,

main line battery 57 being likewisegrounded at ,G, the party callingfirst opens the -main line as usual by throwing theswitch lever 58' tothe right and into the position shown inFig. 6. Groups of circuitclosures spaced in accordance with the combination corresponding to thestation called are then produced by appropriately depressing the key 40,and the current being transmitted on vthe main line at the key 40 in theusual manher by throwing the switch lever 58 to the plate 60. Asheretofore described, this closure of'the mainline circuit breakscircuit at 55, 56, and the magnet 3 thereupon liberates itsarmautre.'Thereis thus produced that forward and back movement of the upright rod10 (see Fig. 3) whereby the driving train is released, and at once thewheel 13 revolves under the spring 15. causing'successive make and breakof the main line from wire 38 to Wheel 13, spring 15, wire 61,- relay42, main line 59. relay 62 at'calling station, 'key 40. and

through ground to main line battery 57.

Each contact at 15 causes relay 62 to close the. circuit of the sounder63 through local battery 64 at the calling station, and, the propercombination of clicks being thus au-' produced in the sounder 63, the Zma-de aware that he hassuctomatically ted theselective instrumeng 39 atthe proper station. I Atithe same time that the answer backkthus operating the sector 32 is turning more slowly unt i'l con "tact" is finallyinade with the spring. 35;

thus closing circuit through the local battery 46 and the coils 65 whichenergize the ma net 66 of the calling signal.

In orderto provide means whereby the Darty calling may be assured thatthe callcession of long and short buzzes is produceding signal 66 is inworking order and is actually in operation, I prefer to add to theorganization of apparatus thus far described a telephonic instrument 41at the calling station, connected by wires 67, 68, with a supplementalcoil 69 wound on the magnet 66, or otherwise in operative inductiverelation thereto. Since operation of the call bell is of courseaccompanied by rapid magnetic changes in the magnet 66, there will beproduced corresponding electric undulations on the wires 67, 68, causinga buzzing noise in the telephone 41.

It is desirable to produce interruptions in the buzzing so caused havingdurations and a particular sequence corresponding to thecode combinationof the particular station where the signal bell is ringing. By thismeans the party calling can identify the station at which he has rungthe bell. For this purpose, I prefer to provide a short circuit by wires70, 71, connected to the extremities of the supplemental coil 69. and tothe springs 15 and 72. This short circuit is closed whenever the spring15 is raised by a tooth on the wheel 13 and at such times, the inducedcurrent being diverted by the short circuit. the telephone .41 issilent. \Vhenever the spring 15 descends between the teeth 14. however.the short circuit is broken and the induced current reaches thetelephone and causes a buzzing. Thus a sucat 41 which identifies thebell which is ringing.

It will be obvious to those skilled in the art that the benefit of theintermittent or pulsating current through the signaling device 6 may bemade available substantially as herein described without actuallywinding the coil intended to reeeiveinduced c urrent therefrom upon thenuignet (i6 itself, and my invention covers any combination orarrangement of parts whereby an instrument sensitive to inducealternating currents (such for instance as a telephone receiver 41) atthe calling station is made t6 receive an answer back signal f"om':acoil or wind ing placed in inductive relation to the circuitthrough thesignaling instrument. will also be understood that the word circuit whenemployed in this.specificat.ion or in the claims is used in abroad senseand may include a complete circuit from battery back to battery, or onlysuch portion of a circuit as may include the coils of one or more. oftbevarious devices forming a portion of the system disclosed herein.

The apparatus thus far described is suflicient. by itself to accomplishall the objects had in view. assuming that. the operation of themechanism liberated by the magnet 3 is never interrupted. Iiut inasmuchas the answer back wheel 1?, and spring 15 are necessarily included inand operate directly upon the main line circuit, it becomes important touard against a possible interruption of said circuit by accidentalarrest of the wheel at a wrong time. It is clear that,

'if by any accident (as by breakage of the dering the entire main linewire useless from one end to the other. I therefore prefer to employsupplemental means for preventing such a catastrophe. in combinationwith the apparatus hitherto described. Broadly considered, theparticular means herein shown for the above purpose, comprises a circuitcloser for closing the main line circuitaround the spring 15 and wheel13, restraining means therefor, a -device for releasing the circuitcloser and means operated by the answer back device for controllingoperation of said device.

In detail as shown the circuit closer comprises a lever 73 looselypivoted at 74 and carrying a contact/pin 75 which falls against thestationary contact spring 76,- when the lever 73 is released. Thelever'73 being in electric connection with the main frame 2 is connectedelectrically to the Wheel 13 as indicated by the wire 77 in Fig. 6. Thespring 7 6 is mounted upon insulation 78 and is connected by the wire 79with the spring 15. It will thus be seen that when the lever 73 falls,

on the lever 73, whereby said lever is sup ported and prevented fromfalling, thus preventing contact of the pin 75 with the spring 76. Alsofixed to the pivot 81, but; at the opposite side of the apparatus, adepending too the contact pin 75 touching the spring 7 6 will close'abranch aroundreleasing lever 83 is provided, the lower end of which isbent laterally so as to normally touch the stop plate 84, adjustablyfixed to the frame 2 at 85 (see Fig. 2). These elements serve to adjustthe extent ofnormal engagement between-the hook 80' and the. lip 82, andthe lever 83 also provides means whereby the book 80 may be moved out ofengagementwith said lip 82. The preterred mechanism for this purpose isconstrut-ted as ,follows: Outside of the frame 2 a stout wire or rod 86forms an adjustable inclined track upon the top of which rolls the axis87 of the two inertia wheels 88.

. turn are the frame. I

As shown in Fig. 1, the lateral extension extremity 'of the lever 90,pivoted at 91 to of the releasing lever 83 projects into the path inFigs. 2 and 'from the lip i by which as thereupon-' begin toroll slowlydown the the spring 15 is depressed are of the inner arm 89, so that, asthe inertia wheels 88 slowly roll down the track 86, said arm will pushagainst said extension and, by moving it and the hook 80 to the right 3,will disengage the hook 80 "be made by the pin 75. Normally this act-ion is prevented by the depending arm 92, whose lateral extension 93projects across both wheels 88 and pushes them. to the left in Fig. 2,so as to bring the arm 89 against the stop 94. The upper end of the arm92 is rigidly fixed on the lever 95 pivoted at 96, and this lever isnormall supported by a light curved finger 97 l ixed to an insulatinglever 98 pivoted at 99 and whose ,outer end bears'upon the u per side ofthe spring 15 (see Fig. 2). s the Wheel 13 revolves, and each time thatthe contactspring 15 dips downward between two teeth 14, the outer endof the lever 98 follows this downward movement, causing the extremity ofthe finger 97 to descend a disr tance as many times greater than thattraversed by the spring 15 as the length ofthe finger 97 exceeds thelength of the lever 98 it is carried. This permits the lever 95 to movedownward by causes the arm 92 to move'to t Fig.2, freeing the inertiawheels e right in 88, which track 86.

When the answer back is operating nor-j uring which mally the intervalsof time so short that the {finger 97 restores .the lever 95 and armlever 83. Thus the arm 92 prevented. This normal 92 to the positionillustratedbefore the slowly moving wheels 88 have time to bring the arm89 into contact with the releasing pushes the arms 89 back to theposition illustrated without and so closure of the'main line at thespring 76 is normally return movement of the retarding mechanism isaccomplished by sliding the axis 87 back along the track 9 18 6 withoutrotation of the inertia wheels 88, and this occurs instantly and withoutappreciable' retardatio N If any accident the wheel 13 either fails t6turn or is arrested during its operation, one'of-two conditionsproduced. lfithe spring 15 is nidingon a" tooth 14 at sucha time, theniain line circuit is main,-

tained intact by contact between said spring 3 and tooth. If, on theother hand, the wheel 13stops while the spring 15' is depressed betweentwo teeth, leaving the main line 82, thus allowing contact to'telephonic or avity and open at that point, the finger 97 will also bedepressed and the arm 92 will leave the wheels 88 free to roll farenough so that the arm 89 strikes the lever 83, causing the hook 80 torelease the lever 78 and permit the pin 7 5 to close themain linecircuit at '76. Thus accidental failure of operation of the answer-backcan at no time interrupt the main line circuit.

While I have shown my apparatus organized so as totransmit a code signalfrom the station called to the calling station both telegraphically andtelephonically, either the I telegraphic communication may be used alonewithout departing from my invention. It is also to be understood thatthe particular arrangement and combination of instruments abovedescribed are merely illustrative and that many changes, modificationsand additions canbe made in the same without departing from myinvention, which is not limited in its scope to these details. I haveused reference numerals in certain of the following claims, the betterto identify the elements referred to, but the use of'such numerals isnot intended to limit the scope of such claims to the precise form ofsuch element as illustrated herein. What I claim is- 1 In apparatus ofthe class described, in-

combination, an electrically operated an swer back signaling means, alocal signal, a second answer. back signaling means located in inductiverelation to the local signal, selecting means for controlling theoperation of both of saidaiiswer back signaling means and said localsignal.

' 2. In apparatus of the class described, in combination, electricallyoperated answer back signaling means, a local signal, a sec- 0nd answerback signalin means located in inductive relation to sai local signal,se-

lecting means for controlling the operation of said answer backsignaling means, and means for producing a number of operations of oneof said answer back signalin means while continuing the operation of te' local signal.

3. Ailevice of the class'describedcoinprising an actuating gear train, acheck wheel driven thereby, two egs thereon on diflerent radii and at diercnt distances from the center of the wheel, a tilting rod adapted toengage successively with said pegs, an operating arm for said rod, anormally bowed spring in operative relation to said arm and anelectro-magnet and armature arranged to straighten said spring foroperation of said arm, substantially as de scribed.

4. A device of the class described comprising an electrically operatedlocal signal, an electrically actuated answer back, acircuit, for thelatter a section of which isplaced in inductive relation to said signalcircuit, a short circuit across the ends of said inductively placedcircuit-section and automatic means for opening and closin said shortcircuit, substantially as describe signal, common operating mechanismfor both, a telephonic answer back, means for supplying current to thelatter controlled by said local signal, and means for producingprearranged modifications in said current controlled by said telegraphicanswer baclg substantially. as described.

7. A device of the class described comprising an electromagnetic si nal,an operating magnet therefor, an inductively operated answer backsignal,a circuit therefor comprising a coil upon said operating magnet, a shortcircuit around said 0011, and means for making and breaking said shortcircuit, substantially as described.

8. In apparatus of the class described in combination, a circuit fortransmitting s gnaling impulses from a calling station,- a local signal,a circuit for said local signal, selecting means for controlling the.operation of said local signal, answer back means in inductive relationwith the circuit of said local signal, and an answer back receivingdevice in the calling station.

9. In apparatus of the class described, in combination, a circuit fortransmitting signaling impulses from a calling station, a local signal,a circuit for said local signal,

selecting means for controlling the operation of said local signal,answer back meansin inductive relation with the circuit of said localsignal, an answer back receiving device in the calling station, 'abranch circuit about said answer back means, and means for momentarilyopening and closing said branch circuit.

10. In apparatus of the class described, in combination, a circuit fortransmitting signaling impulses from a calling station, a local signal,a circuit for said local signal, selecting means for controlling theoperation of said local signal, answer back means in inductive relationwith the circuit of said local signal, an answer back receiving de- Ivice in the calling station, and meansfon stance rendering the action ofsaid answer back means intermittent. I 11. Apparatus of the classdescribed comprising a circuit for transmission of signals, an answerback signaling device in said circuit, a circuit closer in a brancharound said answer back, means for operating said circuit closerincluding reciprocating retarding means operative in'one direction onlyand mechanism operated by movements of said answer'back device foralternately releasing and pushing back said retarding means,substantially as described.

12. In combination an answer back signaling device, a circuit closer ina branch circuit around said device, a device forclosing circuit throughsaid circuit closer, means for applying operative pressure to saiddevice, a retarding device for said last named ineans,'and mechanismoperated by movements of said answer back device for controlling theaction of said retarded pressure applying means, substantially asdescribed.

13. In combination an answer back sig nailing device. a circuit closerin a branch circuit around the same, a device for closing circuitthroughsaid circuit closer,a reciprocating means for applying operativepressure to said device, a retarding device for said last named meansoperative in one direction only, and mechanism operated by movements ofsaid answer back device for alternately pushing said reciprocating meansin its unretarded direction and releasing it to permit rctarded movementthereof, substantially as described.

14. In combination an answer back signaling device, a circuit closer ina branch circuit around the same, a device for closing circuit throughsaid circuit closer, means operated by gravity in one direction topro-"its upper position after each movement in an operative direction,substantially 'as-described.

15. In combination an answer back sig naling device. a circuit closer ina branch circuit around the same, a device for closing circuit throughsaid circuit closer, a reciprocating means for applying operativepressure to said iast named device and mechanism operatively connectedwith said answer back device for normally arresting movement of saidreciprocating means before it reaches the circuit closing device and soarranged as to be inoperative when the answer babk device stops 'on opencircuit, substan tiiQlly as described.-

- 16. An answer back signaling device-coniprising a toothed wheel and amovable 0011-- {act device adapted to alternately rise upon. thewheelteeth and sink between them; in

" i hai'iswer back receivin averse combination with a circuitcloser in abranch I around said answer back and mechanism op I erated by the riseand fall of said contactdevice for mntrolling operation of said cir-6cuit closer, substantially asdescribed. 17. In combination an answerback signaling device, a circuit closer in a branch cirfcuit around thesame and comprising a gravity lever and cooperating contact piece, a N10 pivoted hook "for supporting said lever and an arm for tripping saidhook; in combination with an inclined/track, a Substantially horizontalpivoted lever (as 90) an upright [lever (as .89) pivoted 'tos'aidhorizontal le- 7 rev so as toswing against said tripping arm, aretarding wheel pivoted .to said upright level-and rolling on saidtrack, and means f oiierated by said answer back device for con- 7 j f"trolling the movements of said wheel and its attached levers.substantially i s described.

" n 18. An answer back; signaling device comprif-ii'ng a \vheelhavingteeth, and a mo ma "jing contact piece adapted to alternately ride 1upon and dip between said teeth, a pivoted 26 lever (as 98) bearing uponsaid contact aro'i'ind said answer back, a restraining de- 1 vicetherefor, retardingtripping means for said device, a substantiallyhorizontal piv- 'BQoted lever (as 95), an arm fixed theretoand fqnnplngmg upon said .retarded tripping means for its operatiomand afinger fixed to I .saidlever 98 and bearing against said lever I '95 foroperatingthe latter,substantially as desc1'ibed. I

19 Atlevice theclass described comprising in' combination an answer-backwheel capable of short initial ,movement :Hwithout operation of'tlioanswer-back, a 40 starting device capable of successive forward andbackward movement,means connected with saidwhee-l andc'otiperating withsaid starting device for producingshort initial movement of said device'a-ndcomplete liber- 46 'ation of the a wheel on the: next backwardmovement of saidv device-an. electro-magnet governing said startingdevice, and selec-- tively operatedmechanism forsuccessively making fand breaking the circuit of said to magnet,substantially as described. 120. In" combination; a -calling station, a-

main line connected therewith, anumber of Y sub-stationsconnected withsaid main line, a

. selective signal operator and local signal cir- '55 cuitlat eachsub-station, asignal operated thereby at each station arranged producerapid potential changes-when, operated, an devicea't the calling stationand a circuit connected to said j ,answeraback receiving device and'arranged ini-nductive relation to the signal circuits in saidsubstations, substantiallyas described. 91. in combination, a callingstation, a "main line connected therewith, a numberof piece,- a circuitcloser in a branch circuit.

answer-back receiving device at the calling station,-a circuit connectedto said answer-F back receiving device, a local inductive circuit ateach sub-station in inductive relation to said local signal circuit,means controlled by-said selective signal operator for producingidentifying changes in the condition of each of said local inductivecircuits.

22. In a signaling system in combination,

.a signaling circuit, a local signal, answer back means combined withsaid local signal and located in inductive relation with said signalingcircuit. means for impressing impulses upon said signaling'circuit, andselecting mechanism for controlling said last named'means.

'23. In a signaling system in combination, a signaling circuit, a. localsignal, acircuit for said localsignal, automatically 0 eratedv answerback means combined with said local .signal and located in inductiverelation with said signaling circuit. means for impressing impulses uponsaid signaling circuit, and selecting mechanism for controlling saidlast named means. n

24. In a signaling system, in combination, an instrument for impressingsignaling impulses upon the line, a local signahanswer back meanslocated in inductive relation with the local signal, an answer backreceiving instruinent,,and selectingmeans operated by thesignalingimpulses impressed upon the line from the signaling station forI controlling the operation of the local signal.

In a signaling system, thecombination with a line connecting a callingand. a

called station, ofan instrument at the'calle mg station'for lmpressingsignaling impulses on the line, a selector at the called stationselectively o erated by definite, predetermined .sign'aing impulses, anelectro magnetically operated signal includin a vibrating member at thecalled station, tieelectromagnet. of said signal directly operating saidvibrating member and having a normally open local circult controlled bysaid selector,

and an electrically actuated answer back receivin instrument-at thecalling station arranget 1n circuit to'rece1ve a flow of current memberof said local signal.

' 26. In a signaling system, the combination with a'line connectlngacalling and a called station, of an instrument at the calling stationfor impressing signaling. impulses on the line, alselector at the calledstation selectively operated by definite. predetermined signalingimpulses, impressed on the line by said instrument, anelectro-magnetically opvaried by the operation of the vibrating circuitof said local signal, whereby the conthe line, a selector at the called.station seerated local signal at the called station hav- I ing itscircuit controlled by said selec or, and an electrically actuated answerback receiving instrument at the calling station ar ranged in circuit toreceive induced currents resulting from the operation of saidelectromagnetically operated local signal.

27. In a signaling system, the combination with a line connecting acalling and a called station, of an instrument at the calling stationfor impressing si%1aling impulses on the line, a selector at t e calledstation selectively operated by definite, predetermined signalingimpulses, an electro-magnetically operated local signal at the-calledstation having its circuit controlled by said selector, and anelectrically actuated answer back receiving instrument at the callingstation, responsive to a current flow of varying potential, said answerback receiving instrument having its circuit operatively related to thetinned and rapid interruption of the current flow of the circuit of thelocal signal resulting from the operation of said local signal producesa current flow of varying potential through said answer back receivinginstrument. i

28. In a signaling system, the combination with a line. connecting acalling and a called station, of an instrument at the calling stationfor impressing signaling impulses on let-tively operated by saiddefinite, predetermined signaling impulses, an electro-magneticallyoperated local signal at the called station having its circuitcontrolled by said selector, and an electrically actuated answer backreceiving instrument at the calling station, the coils of theelectro-magnet of said local signal being operatively related to thecircuit of said answer back receiving instrument to produce therein avariable current flow. M 29. In a signaling system, the combinatipn withan instrument at the calling station for impressing electrical signalingimpulses and a selector at a called station i'espons'weto definite,predetermined signaling ini'pnlsesl a i J ment, of anelectro-magnetically operateu signal including a vibrating member at thecalled station, the electro-magnet of said signal directly operatingsaid vibrating member and having a normally open circuit arranged to beclosed by the operation of said selector, an electrically actuatedanswer back receiving instrument at the calling station.

responsive to currents of variable potential produced by the operationof the vibrating member of said signal, and a system of circuitselectrically connecting said instrument for impressing electricalimpulses on the line and said selector, and for also electrically conmeeting said electro-magnetically operated signal and said answer backreceiving instrument.

30. The combination with a system of circuits. of an instrument forimpressing electrical signal impulses and a selector Operativelyresponsive only to definite, redetermined signaling impulses connecte insaid system of circuits at a calling andcalled station, respectively, anelectro-magnetically actuated signal at the called station having itscircuit controlled by said selector, and an answer back receivinginstrument at the called station electrically connected by means of saidsystem of circuits with the coils of the electro'magnet of said signal.31. In a signaling system, the combination with a main line connecting acalling and a called station, of a local signaling circuit at the calledstation,,means for selectively controlling said signaling circuit, asignal in said signaling circuit arranged to produce rapid potentialchanges when operated, and an electrically actuated answer backreceiving device at the calling station having its circuit operativelyrelated to the circuit of said local signal, whereby rapid'potentialchanges in the signaling circuit produce corresponding potential changesin the circuit of said answer back receiving device.

.. EDWIN a. GILL. Witnesses:

H. S. MACKAYE, .TA Mns S. LAING.

produced by the operation of said instru- F

